arjay

The centre air vent on my 964 3.6T has developed a sort of whirring/clicking sound when on lowest fan setting. It stops when the fan is switched off. It is noisy enough to be quite intrusive but liveable with - just put the fan on a higher setting and enjoy a normal noisy fan

When driving and turning to the left, the noise stops but comes back straight ahead or turning right. My first guess is that a cable to the fan has got snagged or is binding on the steering in some way.

I have had the clock/speedo out and also the radio to see if I can get to the back of the vent or a fan but no go. Tried feeling around behind the dash in the column area but can't find anything that might be a fan cable or whatever. Never having been behind the dash I have no idea of the layout of the air vent/fan system.

Can anyone help me out please?

Ta

John McM

This is a common 964 problem with plenty of advice on their forum, just search e.g.

https://rennlist.com/forums/964-foru...ing-sound.html

964X33

My guess it is one of the heater blowers in the front luggage compartment behind the firewall; I have this problem now. There is a plastic cover on top which comes off with two screws then you can stick your ear next to each one to determine the culprit. Apparently the front of the blowers (one each side) slide up after removing a couple of clips to reveal the squirrel cage. Sounds like the full repair is to remove the fan and drip some oil into it (or replace it at great expense) but I'm gonna try some spray on lube when I get round to it (in the meantime I've disconnected it). Try http://forums.rennlist.com/rennforum...ice-970-a.html
Alternatively it could be your CCU fan which is easily fixed (search CCU fan).

arjay

Thanks for your link but actually this is for an engine fan problem. Mine is something to do with the central air vent in the dash.

I take your point about searching first. I did actually do some searching - perhaps I should have mentioned what I found in the first post. What I mainly found was stuff on engine fans and also the small fan on the back of the CCU unit.

I discounted the CCU fan because I thought that was controlled independently by oil temp etc, whereas I can turn this noise off by turning off the fan control on the dash. Also, the noise stops when turning the steering wheel one way and starts again when turning the other way - I thought this might be a cable snagging somewhere.

[Another reason I had trouble finding other posts was that much seems to be posted under heater blowers rather than air vents/fans or variations thereof.] Didn't know they were called this

arjay

I take it these would be directly behind the centre fascia air vents? Thanks for the tip - at least I now know where to go looking. I am going to try advice on this forum about dripping oil down onto the bush pads and bearings. But I also suspect that a cable or something is pulling on the fan (blower or whatever) causing it to distort and squeak.

Maybe it always pulled on the blower but has only now become apparent because the bearings have dried out?

Don't think it is this - see my previous post.

Apologies for not replying earlier - never got the email advising a reply.

John McM

Oops. Should have read further into the thread. Good luck with the repairs. Nothing more satisfying than knowing you don't have to run to a mechanic for everything. I think of my small fixes to date as bonding time.

arjay

NZ964C4 if you are still watching this thread. Or anyone come to that.

I have been following different guides to getting at the heater blowers for the central air vents on my 964T. I have got the grill off under the back edge of the bonnet/hood/trunk whatever I should call it where I thought these suckers would be. All I find is a mass of stuff like the wiper motors and some other bits and pieces I don't recognise.

There is no way I could get even a human hair in there and down to bearings on the blowers - so I can drip some oil on them as other posts say. Am I in the right place? Here is a pic of what I found.

BTW - this link only gives a 404. Anyone know what it refers to? I've searched the forum but can't turn it up...

wagonface

What you can see in your photo are 4 or 5 little servo motor thingys - they change where the air goes (windscreen, feet) and I think they mix cold and hot air. The system is massively over engineered and complicated and very expensive to repair now that parts are scarce. The 2 front blower motors are all the way to the left and right hand side of your picture. I had to replace both of mine, cheap at £400 each. Apparently you need to remove all that stuff in your picture to get access to the motors, so I also paid c.4hrs labour. £1,200 to replace some fans that are crap even when working properly? Awesome.

Some people on here have re-oiled the fans, but I can't comment on how successful that is. If you are doing the work yourself then maybe try it, all you have lost is time. If you are paying someone to do it then I would suggest biting the bullet and getting new fans, otherwise you will pay labour twice. Good luck.

arjay

Many thanks for your help. Now I know I am in the right place, I'll have more of a detailed look. Not paying that sort of money for a fan!! I'll just put up with the irritating noise - they work OK.

Still haven't figured out why the noise stops when I turn to the left but starts again when straight ahead or turning right. Still think there must be a cable or something that is snagging just enough to put pressure on the fan and create this noise.

Thanks again.